(Peter, I CCed this to the groff list since my original message went there, and this way the resolution is in the mailing list archives.)
I tried your wonky-char.mom version with the groff that I built (GNU groff version 1.23.0.rc1.340-0dab6, from a recent git pull) and got exactly the same problem: when I hovered over the link, I saw the "%23" instead of the "#", and when I copied the link from the PDF (using right-click > Copy Link) I got the URL with the "%23", and when I clicked on the link I got a 404 error in my browser. This was in Preview on macOS. I tried it with Acrobat Reader DC on macOS, and it worked fine. I tried it in PDF Expert, and it worked fine. I tried it in mupdf on OpenBSD and it worked fine. I'm convinced this is a bug in Apple's macOS Preview application. Sorry for adding to the noise. -- T. Kurt Bond, tkurtb...@gmail.com, https://tkurtbond.github.io
